The invention is concerned with elevated lighting or other signal fixtures at the top portion of a supporting standard, as a tower or pole structure in street and highway lighting. Repair, replacement or servicing of such fixtures often involves the necessity for service personnel to gain access to the fixture at its elevated position, as by climbing or with use of a service truck equipped with a maneuverable elevator for the service personnel. Under these conditions, unitized replacement fixtures mounted at the elevated position have been provided (U.S. Pat. No. 3,679,891); and to obviate the necessity of service personnel gaining access to the elevated position of the fixture for repair, replacement or other servicing thereof, cable and like mechanisms have been provided for lowering and elevating the fixture to a lower accessible position for service personnel (U.S. Pat. Nos. 3,292,322; 3,686,498; 3,856,639). The mechanisms are relatively expensive and exposed, thus being subject to exteriorly applied damage as well as weather conditions. My copending application, Ser. No. 005,757, filed Jan. 23, 1979, shows another assembly for moving a light or other signal fixture between an elevated operative position and a lower accessible position for servicing.